Relationship between aortic atherosclerosis and non-invasive measures of arterial stiffness

Differences in carotid to femoral pulse wave velocity and carotid intima media thickness between vegetarian and omnivorous diets in healthy subjects: a systematic review and meta-analysis

Background: Arterial stiffness and atherosclerosis are known risk factors for cardiovascular morbidity and mortality. Vegetarian diets have been associated with cardiovascular benefits, including improvements in metabolic parameters. However, the impact of a vegetarian diet on cardiovascular parameters, specifically arterial stiffness and atherosclerosis, in healthy individuals remains unclear. Thus, this study aims to analyze differences in arterial stiffness and atherosclerosis between vegetarian and omnivorous diets in healthy subjects. Methods: A systematic review and meta-analysis were conducted following established guidelines. PubMed, Scopus, Web of Science, and Cochrane Library databases were searched for studies examining the association between vegetarian and omnivorous diets with arterial stiffness and atherosclerosis. Cross-sectional studies reporting carotid to femoral pulse wave velocity (cf-PWv) as a measure of arterial stiffness and carotid intima media thickness (c-IMT) as a measure of atherosclerosis were included. Data were synthesized using random effects models, and sensitivity analyses, meta-regressions, and assessment of publication bias were performed. Results: Ten studies were included in the systematic review, and seven studies were included in the meta-analysis. The pooled analysis demonstrated that individuals following a vegetarian diet had differences in the levels of arterial stiffness (cf-PWv) compared to those following an omnivorous diet (MD: -0.43 m s-1; 95% CI: -0.63, -0.23). Similarly, atherosclerosis (c-IMT) was found to be different in individuals adhering to a vegetarian dietary pattern (MD = -29.86 mm; 95% CI: -58.41, -1.32). Conclusions: Our findings suggest that a vegetarian diet is associated with improved arterial stiffness and reduced atherosclerosis in healthy individuals. These results support the inclusion of a well-balanced vegetarian dietary pattern in the prevention and management of cardiovascular diseases. However, further research is needed to explore the effects of a vegetarian diet on arterial health in diverse populations and to assess long-term cardiovascular outcomes.

Long-Term Passive Leg Stretch Improves Systemic Vascular Responsiveness as Much as Single-Leg Exercise Training

PURPOSE

The current study compared the local and systemic vascular responsiveness after small muscle mass endurance training or passive stretching training (PST).

METHODS

Thirty-six sex-matched healthy participants underwent 8-wk single-leg knee extension (SLKE) (n = 12) training or PST (n = 12), or no intervention (control, n = 12). Before and after the intervention, local and systemic vascular responsiveness was assessed by Doppler ultrasound at the femoral (local effect) and brachial artery (systemic effect) during single passive leg movement and brachial flow-mediated dilation (FMD) test, respectively.

RESULTS

After training, delta femoral blood flow (representing the local vascular responsiveness) increased after SLKE and PST by +54 (7)% (effect size, 2.72; P < 0.001) and +20 (2)% (effect size, 2.43; P < 0.001), respectively, albeit with a greater extent in SLKE (post-SLKE vs post-PST: +56 [8]% [effect size, 2.92; P < 0.001]). Interestingly, the %FMD (standing for the systemic effect) increased after SLKE and PST by +12 (2)% (effect size, 0.68; P < 0.001) and +11 (1)% (effect size, 0.83; P < 0.001), respectively, without any between-groups difference (P > 0.05). No changes occurred in control.

CONCLUSIONS

The present findings revealed that both active and passive training modalities induced similar improvements in the brachial artery dilatation capacity, whereas the former was more effective in improving femoral artery blood flow. Passive stretching could be used in people with limited mobility to improve vascular responsiveness both at the local and systemic level and in this latter case has similar effects as small muscle mass endurance training.

Examination of Large Artery Atherosclerosis could Reveal Small Artery Retinopathy in Untreated Middle-Aged Individuals

AIMS

Small arteries can be visualized in the ocular fundus, and findings of retinopathy based on Scheie classification are often applied to evaluate the impact of hypertension and atherosclerosis. However, the relationship between damage in the large and small arteries has not been investigated sufficiently, especially in the early stages. The present study investigated possible associations between large artery atherosclerosis and small artery retinopathy in untreated middle-aged individuals.

METHODS

Untreated middle-aged workers undergoing periodic health check-ups (n=7,730, 45±8 years) were enrolled in this study. The absence or presence and extent of retinopathy were characterized by ophthalmologists as hypertensive (H0-4) and atherosclerotic grades (S0-4) based on Scheie classification. Large artery atherosclerosis was examined based on functional assessment of the cardio-ankle vascular index (CAVI) and morphological assessment of the carotid intima-media thickness (IMT) by ultrasound.

RESULTS

We found significant differences in CAVI and carotid IMT between individuals with and without hypertensive or atherosclerotic retinopathy. Multivariable regression analysis showed that the presence of hypertensive and atherosclerotic retinopathy was significantly associated with CAVI and carotid IMT. Logistic regression analysis with the endpoint of a hypertensive or atherosclerotic lesion revealed that CAVI and carotid IMT are independent determinants of retinopathy.

CONCLUSIONS

CAVI and carotid IMT were significantly associated with the presence of retinopathy based on Scheie classification in untreated middle-aged subjects, implying that atherosclerotic examination in large arteries could reveal early-stage small artery retinopathy.

A body shape index could serve to identify individuals with metabolic syndrome and increased arterial stiffness in the middle-aged population

BACKGROUND

A body shape index (ABSI) is a novel anthropometric measure calculated using waist circumference (WC), body mass index (BMI), and body height. This study investigated the usefulness of ABSI to identify individuals with metabolic syndrome (MetS) and increased arterial stiffness in the middle-aged population.

METHODS

Middle-aged workers who underwent periodic health check-ups and who were without previous cardiovascular events were enrolled (n = 10,182). In addition to ABSI, visceral fat area (VFA) was evaluated using computed tomography. Obesity and MetS were diagnosed on the basis of WC, VFA, and ABSI. Arterial stiffness was examined by measuring the cardio-ankle vascular index (CAVI).

RESULTS

ABSI was significantly associated with CAVI in multivariable regression analysis. Logistic regression analysis revealed that ABSI was independently associated with the presence of MetS diagnosed on the basis of WC or VFA after adjustment for potential confounders, including BMI. Subjects with MetS diagnosed on the basis of each obesity index showed higher CAVI values than those without. Among subjects with MetS diagnosed on the basis of WC or VFA, those with MetS who met the definition of ABSI obesity showed significantly higher CAVI than those who did not. The other logistic regression analysis demonstrated that CAVI was independently associated with MetS defined on the basis of ABSI.

CONCLUSIONS

ABSI was significantly associated with CAVI and the presence of MetS in the middle-aged population and helped to discriminate individuals with MetS and increased CAVI. ABSI could serve to identify individuals with MetS and increased arterial stiffness.

Early arteriosclerosis and its risk factors in subjects with prediabetes and new-onset diabetes

BACKGROUND

We aimed to investigate early arteriosclerosis and its risk factors in populations with prediabetes and new-onset diabetes.

MATERIALS AND METHODS

A total of 148 participants who did not have diabetes mellitus were assigned to three groups through an oral glucose tolerance test: the normal glucose tolerance (NGT) group; the impaired glucose regulation, also known as prediabetes group and the new-onset type 2 diabetes mellitus group. The insulin resistance index was assessed using the homeostatic model assessment of insulin resistance (HOMA-IR). An ELISA was used to determine the level of fibroblast growth factor 21 (FGF21). An arteriosclerosis detector was used to measure the brachial-ankle pulse wave velocity (baPWV) and ankle-brachial index (ABI). The baPWV, ABI, and FGF21 were used to assess early arteriosclerosis.

RESULTS

Significant differences in age, systolic blood pressure (SBP), fasting plasma glucose (FPG), 2-h plasma glucose (2hPG), 2-h insulin (2hINS), and HOMA-IR were found between the NGT group and the prediabetes and new-onset diabetes groups. All of the above, except 2hINS, showed an increasing trend. Moreover, the FGF21 was higher in the new-onset diabetes group than in the NGT group. The baPWV was higher in the new-onset diabetes group than in the other two groups, but no significant difference was noted in the ABI. Age, SBP, diastolic blood pressure, FPG, 2hPG, and FGF21 were positively correlated with the baPWV. In addition, FPG, SBP, FGF21, and HOMA-IR were independent risk factors for the baPWV.

CONCLUSIONS

Patients with prediabetes and new-onset diabetes may have more significant early arteriosclerosis. The blood glucose level and insulin resistance index may be independent risk factors for early arteriosclerosis.

Evidence for improved systemic and local vascular function after long-term passive static stretching training of the musculoskeletal system

KEY POINTS

Vascular function and arterial stiffness are important markers of cardiovascular health and cardiovascular co-morbidity. Transitional phases of hypoemia and hypermia, with consequent fluctuations in shear rate, occuring during repetitive passive stretching adminstration (passive stretching training) may constitute an effective stimulus to induce an amelioration in vascular function, arterial stiffness and vascular remodelling by improving central and local blood flow control mechanisms. Vascular function, arterial stiffness and vascular remodelling were evaluated before and after 12 weeks of passive stretching training and after 6 weeks from training cessation, in the femoral, popliteal (treated with stretching), and brachial arteries (untreated) of both sides. After passive stretching training, vascular function and arterial remodelling improved, and arterial stiffness decreased in all the arteries, suggesting modifications of both central and local blood flow control mechanisms. Passive stretching-induced improvements related to central mechanisms seemed to have a short duration, as they returned to pre-training baseline within 6 weeks from training cessation, whereas those more related to a local mechanism persisted in the follow-up.

ABSTRACT

Acute passive stretching (PS) effects on blood flow ( Q ̇ ), shear rate ( Y ̇ ), and vascular function in the feeding arteries of the stretched muscle have been extensively investigated; however, few data are available on vascular adjustments induced by long-term PS training. We investigated the effects of PS training on vascular function and stiffness of the involved (femoral and popliteal) and uninvolved (brachial) arteries. Our hypothesis was that PS-induced changes in Q ̇ and Y ̇ would improve central and local mechanisms of Q ̇ control. Thirty-nine participants were randomly assigned to bilateral PS (n = 14), monolateral PS (n = 13) or no PS training (n = 12). Vascular function was measured before and after 12 weeks of knee extensor and plantar flexor muscles' PS training by single passive limb movement and flow-mediated dilatation (FMD). Central (carotid-femoral artery PWV, PWV_CF ) and peripheral (carotid-radial artery PWV, PWV_CR ) arterial stiffness was measured by pulse-wave velocity (PWV), together with systolic (SBP) and diastolic (DBP) blood pressure. After PS training, increases of 30%, 25% and 8% (P < 0.05) in femoral Δ Q ̇ , popliteal and brachial artery FMD%, respectively, occurred in both PS training groups. A decrease in PWV_CF , PWV_CR , SBP and DBP (-25%, -17%, -4% and -8%, respectively; P < 0.05) was noted. No changes occurred in controls. Vascular function improved and arterial stiffness reduced in the arteries involved and uninvolved with PS training, suggesting modifications in both central and local Q ̇ control mechanisms. PS-induced improvements had a short duration in some of vascular function parameters, as they returned to baseline within 6 weeks of PS training cessation.

Arterial Stiffness is Associated with Intracranial Arterial Stenosis other than Dolichoectasia in the General Population

Aims: The relationship between central arterial stiffness and aging-related intracranial arteriopathy is not well investigated in the general population. In a population-based study, we investigated arterial stiffness in relation to intracranial atherosclerotic stenosis and intracranial arterial dolichoectasia.

Methods: This study was a cross-sectional analysis on 1,123 subjects (aged 56.0 ± 9.3 years, 37.9% men) of the population-based Shunyi study in China. Arterial stiffness was assessed by measuring brachial-ankle pulse wave velocity (baPWV). Intracranial atherosclerotic stenosis and intracranial arterial dolichoectasia were evaluated via brain magnetic resonance angiography. Multivariate regression models were constructed to investigate the association between baPWV and intracranial large artery diseases.

Results: Increased baPWV was significantly associated with higher prevalence of intracranial atherosclerotic stenosis (odds ratio for the highest quartile of baPWV compared with the lowest quartile, 3.66 [95% confidence interval, 1.57–8.54]), after adjustment for cardiovascular risk factors in multivariate analysis. BaPWV was not associated with the presence of basilar artery dolichoectasia and dilation of basilar artery and internal carotid artery. When the diameters of intracranial arteries were regarded as continuous variables, increased baPWV was inversely related to the internal carotid artery diameter in fully adjusted models (β ± SE, −0.083 ± 0.042, p = 0.047).

Conclusions: This population-based study demonstrates that arterial stiffness was more likely associated with intracranial stenotic arteriopathy other than intracranial dilative arteriopathy.

Close Association between Subclinical Atherosclerosis and Pulmonary Function in Middle-Aged Male Smokers

AIMS

Cigarette smoking provokes deleterious influences on cardiovascular and pulmonary systems, although the underlying relationship has not been sufficiently investigated especially in early-stage disease. The present study investigated possible associations between subclinical atherosclerosis and pulmonary function in middle-aged male smokers.

METHODS

Male smokers undergoing their periodic health check-up were enrolled in this study (n=3,775, 45±8 years). Pulmonary function was evaluated using spirometry by calculating forced vital capacity (FVC) as a percentage of predicted value (FVC%-predicted), forced expiratory volume in one second (FEV1) as a percentage of predicted value (FEV1%-predicted), and the ratio of FEV1 to FVC (FEV1/FVC). Subclinical atherosclerosis was assessed based on ankle-brachial pressure index (ABI), cardio-ankle vascular index (CAVI), ultrasound examination of the carotid intima-media thickness (IMT), and presence of plaque.

RESULTS

Multivariate regression analysis showed that ABI was positively associated with FVC%-predicted and FEV1%-predicted after adjustment for confounders including smoking intensity, while CAVI or carotid IMT was inversely associated with both. Participants with chronic obstructive pulmonary disease (COPD, n=256) showed reduced ABI and increased CAVI or carotid IMT compared with those without COPD, and participants with carotid plaque had lower pulmonary function than those without plaque. Reduced FEV1/FVC was an independent determinant of carotid plaque and decreased ABI was an independent determinant of COPD, as revealed by logistic regression analysis with the endpoint of carotid plaque presence or a diagnosis of COPD revealed.

CONCLUSIONS

Middle-aged male smokers showed a close association between subclinical atherosclerosis and pulmonary function, implying that smoking induced-vascular and pulmonary damage are interacting in early-stage disease.

Relationships of Obesity-Related Indices and Metabolic Syndrome with Subclinical Atherosclerosis in Middle-Aged Untreated Japanese Workers

Aim: Obesity is a social problem due to the prevalence of the Western lifestyle. In particular, visceral fat accumulation, which is a main component of metabolic syndrome, is closely associated with the progression of atherosclerosis. This study aimed to investigate the relationships of obesity-related indices and metabolic syndrome with subclinical atherosclerosis in middle-aged untreated workers.

Methods: Employees undergoing their periodic health check-up but without previous cardiovascular events or cardiovascular medications were enrolled in this study (n = 7,750). Body mass index (BMI), percent body fat, waist circumference, and visceral fat area were evaluated as obesity-related indices. Assessment of visceral fat area was performed by computed tomography (CT). Subclinical atherosclerosis was assessed by measuring arterial stiffness using cardio-ankle vascular index (CAVI) and by ultrasound examination of carotid intima-media thickness (IMT).

Results: Obesity-related indices were significantly correlated with each other and were positively associated with carotid IMT but negatively associated with CAVI in multivariate regression analysis. In a logistic regression analysis including CAVI and carotid IMT simultaneously, CAVI was negatively associated, but carotid IMT was positively associated, with obesity defined by each obesity-related index. In contrast, both CAVI and carotid IMT were positively associated with the presence of metabolic syndrome based on visceral fat accumulation.

Conclusions: Obesity-related indices were negatively associated with CAVI and positively associated with carotid IMT in middle-aged untreated workers, while both CAVI and carotid IMT were worsened in the presence of metabolic syndrome.

Multispecies Probiotic Supplementation Favorably Affects Vascular Function and Reduces Arterial Stiffness in Obese Postmenopausal Women-A 12-Week Placebo-Controlled and Randomized Clinical Study

Obesity in the postmenopausal period is associated with an increased risk of cardiovascular diseases in women. One of the key drivers of cardiovascular risk is endothelial dysfunction; thus, this is also a crucial point for studies on new therapeutic methods of cardioprotective properties. The aim of the current study was to evaluate the effect of two doses of multispecies probiotic Ecologic® Barrier supplement on functional (primary endpoint) and biochemical parameters (secondary endpoint) of endothelial dysfunction in obese postmenopausal women in a 12-week randomized, placebo-controlled clinical trial. A total of 81 obese Caucasian women participated in the trial. The subjects were randomly assigned to three groups that received a placebo, a low dose (LD) (2.5 × 10⁸ colony forming units (CFU) per day), or a high dose (HD) (1 × 1010 CFU per day) of lyophilisate powder containing live multispecies probiotic bacteria. The probiotic supplement was administered each day for 12 weeks in two equal portions. A high dose probiotic supplementation for 12 weeks decreased systolic blood pressure, vascular endothelial growth factor, pulse wave analysis systolic pressure, pulse wave analysis pulse pressure, pulse wave analysis augmentation index, pulse wave velocity, interleukin-6, tumor necrosis factor alpha, and thrombomodulin. Low doses of probiotic supplementation decreased the systolic blood pressure and interleukin-6 levels. The mean changes in the estimated parameters, compared among the three groups, revealed significant differences in the vascular endothelial growth factor, the pulse wave analysis systolic pressure, the pulse wave analysis augmentation index, the pulse wave velocity, the tumor necrosis factor alpha, and thrombomodulin. The post hoc tests showed significant differences for all parameters between HD and the placebo group, and HD and LD (besides pulse wave analysis augmentation index). We show for the first time that supplementation with multispecies probiotic Ecologic® Barrier favorably modifies both functional and biochemical markers of vascular dysfunction in obese postmenopausal women.

Seafood Long-Chain n-3 Polyunsaturated Fatty Acids and Cardiovascular Disease: A Science Advisory From the American Heart Association

Since the 2002 American Heart Association scientific statement "Fish Consumption, Fish Oil, Omega-3 Fatty Acids, and Cardiovascular Disease," evidence from observational and experimental studies and from randomized controlled trials continues to emerge to further substantiate the beneficial effects of seafood long-chain n-3 polyunsaturated fatty acids and cardiovascular disease. A recent American Heart Association science advisory addressed the specific effect of n-3 polyunsaturated fatty acid supplementation on clinical cardiovascular events. This American Heart Association science advisory extends that review and offers further support to include n-3 polyunsaturated fatty acids from seafood consumption. Several potential mechanisms have been investigated, including antiarrhythmic, anti-inflammatory, hematologic, and endothelial, although for most, longer-term dietary trials of seafood are warranted to substantiate the benefit of seafood as a replacement for other important sources of macronutrients. The present science advisory reviews this evidence and makes a suggestion in the context of the 2015-2020 Dietary Guidelines for Americans and in consideration of other constituents of seafood and the impact on sustainability. We conclude that 1 to 2 seafood meals per week be included to reduce the risk of congestive heart failure, coronary heart disease, ischemic stroke, and sudden cardiac death, especially when seafood replaces the intake of less healthy foods.

Inhaled Corticosteroids in Asthma: Promoting or Protecting Against Atherosclerosis?

Background

Bronchial asthma is an inflammatory disease of the respiratory system. However, it may also induce systemic effects. Although reports suggest patients with asthma are at increased risk of cardiovascular events, the association between asthma and atherosclerosis is unclear. The aim of the present study was to compare the progression of atherosclerosis between patients with asthma treated with inhaled corticosteroids and healthy controls.

Material/Methods

In 102 adult patients with asthma, markers of arterial stiffness (pulse wave velocity and augmentation index) were evaluated by applanation tonometry. Structural atherosclerotic changes (intima-media complex thickness and presence of atherosclerotic plaque) were assessed sonographically. Lipid profile and fasting glucose level were measured. Clinical data concerning the course of asthma, its severity, and management strategy were obtained. A group of 102 healthy, age-matched controls were examined according to the same protocol.

Results

The majority of patients presented well-controlled asthma of moderate severity. When adjusted for weight, age, and systolic blood pressure, no significant differences were observed in pulse wave velocity, in augmentation index, or in intima-media complex thickness between groups. In controls, atherosclerotic plaque occurred significantly more often than in patients with asthma (p=0.0226). Moreover, in patients with asthma, the intima-media complex thickness of the right common carotid artery was significantly correlated with forced expiratory volume in 1 second (R²=−0.2951, p=0.0083). There was no significant difference in any of the atherosclerosis markers between different types and doses of administered inhaled corticosteroids.

Conclusions

Patients with bronchial asthma presented a decreased risk of atherosclerosis in comparison to healthy controls.

Feasibility of two-dimensional speckle tracking in evaluation of arterial stiffness: Comparison with pulse wave velocity and conventional sonographic markers of atherosclerosis

Objective Arterial stiffening is an early marker of atherosclerosis that has a prognostic value for cardiovascular morbidity and mortality. Although many markers of arterial hardening have been proposed, the search is on for newer, more user-friendly and reliable surrogates. One such potential candidate has emerged from cardiology, the speckle-tracking technique. The aim of this study was to evaluate the feasibility of the two-dimensional speckle tracking for the evaluation of arterial wall stiffness in comparison with standard stiffness parameters. Methods Carotid ultrasound and applanation tonometry were performed in 188 patients with no cardiovascular risk factors. The following parameters were then evaluated: the intima-media complex thickness, distensibility coefficient, β-stiffness index, circumferential strain/strain rate, and pulse wave velocity and augmentation index. These variables were compared with each other and with patient age, and their reliability was assessed with Bland-Altman plots. Results Strain parameters derived from two-dimensional speckle tracking and intima-media complex thickness correlated better with age and pulse wave velocity than standard makers of arterial stiffness. Moreover, the reliability of these measurements was significantly higher than conventional surrogates. Conclusions Two-dimensional speckle tracing is a reliable method for the evaluation of arterial stiffness. Therefore, together with intima-media complex thickness measurement, it offers great potential in clinical practice as an early marker of atherosclerosis.

Oxidative Stress is Closely Associated with Increased Arterial Stiffness, Especially in Aged Male Smokers without Previous Cardiovascular Events: A Cross-Sectional Study

Aim: Cigarette smoking is one of the major risk factors for cardiovascular diseases and induces deleterious vascular damage. Oxidative stress is involved in vascular inflammation, the process of atherosclerosis. The purpose of the present study was to investigate whether the effects of oxidative stress on the arterial wall differ between smokers and non-smokers.

Methods: Male smokers and non-smokers without physical deconditioning who visited Enshu hospital for an annual physical check-up were enrolled in the study. To assess oxidative stress, serum levels of derivative reactive oxygen metabolites (d-ROM) were measured. The radial augmentation index (RAI) was measured using an automated device and was used as an index for arterial stiffness.

Results: Univariate and multivariate linear regression analysis showed that RAI was independently associated with d-ROM levels only in smokers. Moreover, RAI was significantly higher in smokers than in non-smokers. Logistic regression analysis with the endpoint of a higher RAI than the mean revealed that older age (> 65 years), hypertension, and smoking were independently associated with higher RAI. Similarly, logistic regression analysis with the endpoint of higher d-ROM levels than the mean showed that older age and smoking were independently associated with higher d-ROM levels.

Conclusions: Increased RAI is significantly associated with smoking and, in smokers, with increased d-ROM levels. These results suggest that the effects of oxidative stress on arterial properties differ between smokers and non-smokers and that oxidative stress is closely associated with arterial stiffness, especially in smokers.

Arterial indices and serum cystatin C level in individuals with occupational wide band noise exposure

BACKGROUND

Chronic exposure to noise is known to cause a wide range of health problems including extracellular matrix (ECM) proliferation and involvement of cardiovascular system. There are a few studies to investigate noise-induced vascular changes using noninvasive methods. In this study we used carotid artery intima-media thickness (CIMT) and aortic augmentation as indices of arterial properties and cystatin C as a serum biomarker relating to ECM metabolism.

MATERIALS AND METHODS

Ninety-three male participants were included in this study from aeronautic technicians: 39 with and 54 without a history of wide band noise (WBN) exposure. For better discrimination, the participants were divided into the two age groups: <40 and >40 years old. Adjusted aortic augmentation index (AI) for a heart rate equal to 75 beats per minute (AIx@HR75) were calculated using pulse wave analysis (PWA). CIMT was measured in 54 participants who accepted to undergo Doppler ultrasonography. Serum cystatin C was also measured.

RESULTS

Among younger individuals the mean CIMT was 0.85 ± 0.09 mm and 0.75 ± 0.22 mm in the in the exposed and the control groups respectively. Among older individuals CIMT had a mean of 1.04 ± 0.22 mm vs. 1.00 ± 0.25 mm for the exposed vs. the control group. However, in both age groups the difference was not significant at the 0.05 level. A comparison of AIx@HR75 between exposure group and control group both in younger age group (5.46 ± 11.22 vs. 8.56 ± 8.66) and older age group (17.55 ± 10.07 vs. 16.61 ± 5.77) revealed no significant difference. We did not find any significant correlation between CIMT and AIx@HR75 in exposed group (r = 0.314, P value = 0.145) but the correlation was significant in control group (r = 0.455, P value = 0.019). Serum cystatin C level was significantly lower in individuals with WBN exposure compared to controls (441.10 ± 104.70 ng/L vs. 616.89 ± 136.14, P value < 0.001) both in younger and older groups.

CONCLUSION

We could not find any evidence for the association of WBN exposure with arterial properties, but cystatin C was significantly lower in the exposed group.

Pulse Wave Analysis by Applanation Tonometry for the Measurement of Arterial Stiffness

The aim of our study was to investigate the association between pulse wave velocity (PWV) and pulse wave analysis (PWA)-derived measurements for the evaluation of arterial stiffness. A total of 20 (7 male and 13 female) healthy, non-smoking individuals, with mean age 31 ± 12years were included. PWV and PWA measurements were performed using a SphygmoCor apparatus (Atcor Medical Blood Pressure Analysis System, Sydney Australia). PWV significantly correlated with all central aortic haemodynamic parameters, especially with pulse pressure (PP) (p < 0.0001), augmentation index corrected for 75 pulses/min (AI75) (p = 0.035) and augmentation pressure (AP) (p = 0.005). Male subjects presented significantly higher PWV compared with females (p = 0.03), while there were no differences in PP, AP and AI75. In conclusion, PWA is strongly correlated with PWV as a method for the evaluation of arterial stiffness.

Carotid atherosclerosis is associated with left ventricular diastolic function

BACKGROUND

It has been reported that carotid intima-media thickness (IMT) correlates with the risk of stroke or cardiovascular disease. The purpose of this study was to analyze the relationships between echocardiographic findings and carotid atherosclerosis.

METHODS

A total of 234 patients (62 ± 15 years) were referred for echocardiography to evaluate the left ventricular (LV) function. The LV ejection fraction, the ratio of the peak velocity of early rapid filling and the peak velocity of atrial filling (E/A), and the peak early diastolic mitral annular velocity (e') were obtained by echocardiography. The maximum IMT (Max-IMT) and plaque score (PS) were measured by carotid ultrasonography within 1 month of the echocardiographic examination.

RESULTS

The mean values of Max-IMT and carotid PS were 2.41 ± 1.23 mm and 8.5 ± 6.3, respectively. The decreased mean E/A (0.94 ± 0.39) and mitral e' (5.5 ± 1.9 cm/s) indicated LV diastolic dysfunction. A good correlation was observed between Max-IMT and PS (r = 0.83, p < 0.0001). It was shown that 2.8 mm of Max-IMT was equivalent to 10.1 of carotid PS, which indicated severe carotid atherosclerosis. In multiple logistic stepwise regression analysis, among the echocardiographic parameters, only e' was independently associated with severe carotid atherosclerosis (Max-IMT ≥ 2.8 mm or PS ≥ 10.1).

CONCLUSIONS

The present study demonstrated that decreased early diastolic mitral annular velocity relates to the parameter reflecting carotid atherosclerosis. Therefore, the presence of severe carotid atherosclerosis may affect LV diastolic dysfunction.

Intima-media thickness of the descending aorta in patients with bicuspid aortic valve

Objective

A bicuspid aortic valve (BAV) is associated with accelerated aortic valve disease (AVD) and abnormalities in aortic elasticity. We investigated the intima-media thickness of the descending aorta (AoIMT) in patients with AVD with or without an ascending aortic aneurysm (AscAA), in relation to BAV versus tricuspid aortic valve (TAV) phenotype, type of valve disease, cardiovascular risk factors, and single-nucleotide polymorphisms (SNPs) with a known association with carotid IMT.

Methods and results

368 patients (210 with BAV, 158 with TAV,); mean age 64 ± 13 years) were examined using transesophageal echocardiography (TEE) before valvular and/or aortic surgery. No patient had a coronary disease (CAD). The AoIMT was measured on short-axis TEE images of the descending aorta using a semi-automated edge-detection technique. AoIMT was univariately (P < 0.05) related to age, blood pressure, smoking, creatinine, highly sensitive C-reactive protein, HDL, valve hemodynamics and BAV. In the TAV subgroup it was also associated with the rs200991 SNP. Using multivariate regression analysis, age was the main determinant for AoIMT (P < 0.001), followed by male gender (P = 0.02), BAV was no longer a significant predictor of AoIMT. AoIMT was still related to the rs200991 SNP in TAV (P = 0.034), and to creatinine in BAV (P = 0.019), when other variables were accounted for.

Conclusions

Intima-media thickness of the descending aorta is not affected by aortic valve morphology (BAV/TAV); age is the main determinant of AoIMT. Genetic markers (SNPs) known to influence IMT in the carotid artery seem to correlate to IMT in the descending aorta only in patients with TAV.

Effects of Add-on Therapy Consisting of a Selective Mineralocorticoid Receptor Blocker on Arterial Stiffness in Patients with Uncontrolled Hypertension

OBJECTIVE

Aldosterone plays an important role in the pathogenesis of atherosclerosis; however, the significance of mineralocorticoid receptor blockade for atherosclerosis has not been fully elucidated. In this study, the effect of add-on eplerenone on the degree of arterial stiffness was examined in patients with uncontrolled hypertension.

METHODS

Forty-seven uncontrolled hypertensive patients who had previously been treated with anti-hypertensive drugs were examined retrospectively. Thirty-two patients received add-on therapy consisting of eplerenone (Group E) and 15 patients received add-on therapy with a Calcium channel blocker (CCB) or an increased dose of CCB (Group C) in addition to their baseline medications. Both the systolic blood pressure (SBP) and diastolic blood pressure (DBP) values were significantly decreased at two and 12 months in Group C. In contrast, neither the SBP nor DBP values were significantly changed at two months and eventually decreased at 12 months in Group E. The degree of arterial stiffness, as evaluated according to the cardio-ankle vascular index (CAVI), did not improve at either two or 12 months in Group C, whereas the CAVI values improved as early as at two months and the improvement was sustained at 12 months in Group E. The extent of change in the CAVI was not associated with the level of changes in the SBP or DBP values in Group E.

CONCLUSION

Treatment with eplerenone added to the patient's baseline medications improves the degree of arterial stiffness as early as at two months after the beginning of treatment, independent of the blood pressure-lowering actions of these drugs in patients with uncontrolled hypertension.

Genetic determinants of arterial stiffness

Stiffness of large arteries (called arteriosclerosis) is an independent predictor of cardiovascular morbidity and mortality. Although previous studies have shown that arterial stiffness is moderately heritable, genetic factors contributing to arterial stiffness are largely unknown. In this paper, we reviewed the available literature on genetic variants that are potentially related to arterial stiffness. Most variants have shown mixed depictions of their association with arterial stiffness across multiple studies. Various methods to measure arterial stiffness at different arterial sites can contribute to these inconsistent results. In addition, studies in patient populations with hypertension or atherosclerosis may overestimate the impact of genetic variants on arterial stiffness. Future studies are recommended to standardize current measures of arterial stiffness in different age groups. Studies conducted in normal healthy subjects may also provide better opportunities to find novel genetic variants of arterial stiffness.

Radial augmentation index is a surrogate marker of atherosclerotic burden in a primary prevention cohort

Arterial stiffness is linked to cardiovascular risk and predicts clinical events independently of peripheral blood pressure. The potential relationship between the augmentation index measured at the radial artery and asymptomatic atherosclerosis remains unclear however. In order to assess relationship between the peripheral augmentation index and traditional risk factors, we estimated cardiovascular risk and presence of subclinical atherosclerosis in a large asymptomatic population in primary prevention. Patients in primary prevention (n = 1007) with at least 1 cardiovascular risk factor were included and radial augmentation index was measured. Maximum common carotid intima-media thickness, the presence of plaque and Framingham 10 year cardiovascular risk score were assessed. The mean augmentation index was 81 ± 13% in a population composed of 55% males (mean age 56 years). The augmentation index differed significantly between men (77 ± 12%) and women (86 ± 12%). In the global population, augmentation index was negatively correlated to height and weight, and positively correlated to cardiovascular risk, age, systolic blood pressure, pulse pressure, diabetes, HDL-Cholesterol, fasting glucose, intima-media thickness and to the presence of plaques. Multivariate analysis in the global and in the male population revealed an independent and positive relationship between augmentation index and intima-media thickness on the one hand, and between augmentation index and the presence of plaque on the other. Our results confirm that there are significant relationships between a surrogate marker of arterial stiffness and subclinical atherosclerosis in a large primary prevention population.

Assessment of arterial stiffness using applanation tonometry

Augmentation index (AIx) and pulse wave velocity (PWV) assess functional and structural aspects of the vascular wall and are independent markers of cardiovascular morbidity and mortality. Like blood pressure, many factors, genetic, structural, and physiological, affect AIx and PWV. AIx and PWV can be assessed noninvasively using applanation tonometry. The technique is simple, but comes with a number of practical and technical limitations that have not been well documented and (or) explored. This review considers pulse wave analysis in the context of cardiovascular disease, and considers its limitations. Data are presented indicating that the placement of the probe is critical, and that the amplitude of the obtained signal is related to the variability in measurements. On a more theoretical note, issues are discussed regarding the applied transfer functions that are built in the devices to assess central AIx from peripheral waveforms. Altogether, PWV and its analysis are useful additions to the arsenal of parameters that can be used to assess vascular health and to estimate vascular risk. Yet, our analysis underscores the necessity for precise operating procedures, and calls for transparency regarding the applied transfer functions of commercial devices.

Association of resting heart rate with carotid and aortic arterial stiffness: multi-ethnic study of atherosclerosis

Resting heart rate is an easily measured, noninvasive vital sign that is associated with cardiovascular disease events. The pathophysiology of this association is not known. We investigated the relationship between resting heart rate and stiffness of the carotid (a peripheral artery) and the aorta (a central artery) in an asymptomatic multi-ethnic population. Resting heart rate was recorded at baseline in the Multi-Ethnic Study of Atherosclerosis (MESA). Distensibility was used as a measure of arterial elasticity, with a lower distensibility indicating an increase in arterial stiffness. Carotid distensibility was measured in 6484 participants (98% of participants) using B-mode ultrasound, and aortic distensibility was measured in 3512 participants (53% of participants) using cardiac MRI. Heart rate was divided into quintiles and we used progressively adjusted models that included terms for physical activity and atrioventricular nodal blocking agents. Mean resting heart rate of participants (mean age, 62 years; 47% men) was 63 bpm (SD, 9.6 bpm). In unadjusted and fully adjusted models, carotid distensibility and aortic distensibility decreased monotonically with increasing resting heart rate (P for trend <0.001 and 0.009, respectively). The relationship was stronger for carotid versus aortic distensibility. Similar results were seen using the resting heart rate taken at the time of MRI scanning. Our results suggest that a higher resting heart rate is associated with an increased arterial stiffness independent of atrioventricular nodal blocker use and physical activity level, with a stronger association for a peripheral (carotid) compared with a central (aorta) artery.

Potential benefits of exercise on blood pressure and vascular function

Physical activity seems to enhance cardiovascular fitness during the course of the lifecycle, improve blood pressure, and is associated with decreased prevalence of hypertension and coronary heart disease. It may also delay or prevent age-related increases in arterial stiffness. It is unclear if specific exercise types (aerobic, resistance, or combination) have a better effect on blood pressure and vascular function. This review was written based on previous original articles, systematic reviews, and meta-analyses indexed on PubMed from years 1975 to 2012 to identify studies on different types of exercise and the associations or effects on blood pressure and vascular function. In summary, aerobic exercise (30 to 40 minutes of training at 60% to 85% of predicted maximal heart rate, most days of the week) appears to significantly improve blood pressure and reduce augmentation index. Resistance training (three to four sets of eight to 12 repetitions at 10 repetition maximum, 3 days a week) appears to significantly improve blood pressure, whereas combination exercise training (15 minutes of aerobic and 15 minutes of resistance, 5 days a week) is beneficial to vascular function, but at a lower scale. Aerobic exercise seems to better benefit blood pressure and vascular function.

The effects of whey protein on cardiometabolic risk factors

Obesity has reached epidemic proportions worldwide. The health consequences of obesity are more dangerous when associated with the metabolic syndrome and its components. Studies show that whey protein and its bioactive components can promote greater benefits compared to other protein sources such as egg and casein. The aim of this paper is to review the effects of whey protein on cardiometabolic risk factors. Using PubMed as the database, a review was conducted to identify current scientific literature on whey protein and the components of the metabolic syndrome published between 1970 and 2012. Consumption of whey protein seems to play an anti-obesity and muscle-protective role during dieting by increasing thermogenesis and maintaining lean mass. In addition, whey protein has been shown to improve glucose levels and insulin response, promote a reduction in blood pressure and arterial stiffness, and improve lipid profile. The collective view of current scientific literature indicates that the consumption of whey protein may have beneficial effects on some symptoms of the metabolic syndrome as well as a reduction in cardiovascular risk factors.

Association of arterial stiffness with obesity in Australian women: a pilot study

This study investigated the arterial stiffness status in overweight/obese Australian women compared with their lean counterparts. Twenty-six Caucasian women were designated into one of two groups: overweight/obese (body mass index [BMI] 25-34.9 kg/m2 [ n=12]) and lean (BMI 18.5-24.9 kg/m2 [n=14]) groups. Participants were assessed for clinical, anthropometric, metabolic, and augmentation index (AIx) measurements. Age was similar between groups (P=.482). BMI was significantly higher in overweight/obese compared with lean participants (30.26±1.09 vs 21.62±0.52 kg/m2, P=.001) as well as the percentage of body fat (40.60±2.43 vs 21.57±1.13, P=.001), waist circumference (91.47±2.77 vs 70.67±1.60, P=.001), and waist/hip ratio (0.81±0.04 vs 0.71±0.03, P=.036). Overweight/obese group showed higher total cholesterol, triglyceride, low-density lipoprotein cholesterol, and fasting glucose levels compared with the lean group (all P<.05). Both systolic (122.92±3.18 mm Hg vs 108.14±2.42 mm Hg, P=.001) and diastolic (83.58±2.43 mm Hg vs 72.43±1.29 mm Hg, P=.0001) blood pressures, as well as AIx (50.08±4.7 vs 120.79±2.17, P=.001) were significantly higher in the overweight/obese group compared with the lean group. AIx was positively associated with measurements of body composition (P<.05), triglycerides (r=0.361, P=.035) and glucose levels (r=0.371, P=.031), and systolic and diastolic blood pressure (r=0.793 and r=0.718, respectively; P=.0001). This data suggests that arterial stiffness is associated with obesity, along with other metabolic abnormalities in Australian women.

Acute effect of calcium citrate on serum calcium and cardiovascular function

Calcium supplements have been associated with an increased risk of cardiovascular events. However, the validity of these findings has been questioned. A major concern is that the mechanism underlying an increase in cardiovascular events has not been demonstrated. Calcium initiates cardiac and vascular contraction following influx of calcium into cardiac and smooth muscle from extracellular fluid. We have investigated whether the acute rise in serum calcium following calcium supplement administration is associated with adverse changes in cardiovascular function. In an open interventional study, we recruited 25 volunteers (16 female, age 60.3 ± 6.5 years, body mass index 25.7 ± 2.7 kg/m2) from the community who were not taking calcium supplements. Participants were studied before and 3 hours after a single oral dose of 1000 mg calcium citrate. We assessed well-validated markers of arterial stiffness (pulse wave velocity [PWV]), arterial wave reflection (augmentation index [AIx]), and myocardial perfusion (subendocardial viability ratio [SEVR]) by pulse wave analysis and endothelial function (reactive hyperemia index [RHI]) by peripheral arterial tonometry. Total and ionized serum calcium were acutely increased by 0.10 ± 0.07 and 0.06 ± 0.03 mmol/L, respectively, 3 hours after calcium citrate administration (p < 0.0001 for both comparisons). Following administration of calcium citrate there was a fall in AIx from a median of 29.7% (23.8% to 34.0%) to 26.4% (22.7% to 34.0%, p = 0.03) and an increase in SEVR from 163% (148% to 174%) to 170% (149% to 185%, p = 0.007). PWV and RHI were not significantly altered. The change in total calcium was negatively correlated with the change in AIx (r = -0.48, p = 0.02). In summary, the acute increase in serum calcium following calcium supplement administration is associated with reduced arterial wave reflection and a marker of increased myocardial perfusion. If maintained long-term, these changes would be expected to reduce cardiovascular risk. Acute serum calcium-mediated changes in these parameters of cardiovascular function are unlikely to underlie an association between calcium supplementation and cardiovascular events.

Effects of psyllium on metabolic syndrome risk factors

High-fibre intake has been shown to reduce the risk of metabolic syndrome (MS), cardiovascular disease and type 2 diabetes. Psyllium is one of the most widely used fibre supplements because it is reasonably cheap and is better tolerated than other fibre supplements. The review of the literature supports the notion that the consumption of psyllium provides benefits to many components of the MS. Psyllium supplementation does improve glucose levels and insulin response, blood pressure, as well as lipid profile in both animals and humans, thereby reducing metabolic risk factors. Appetite has also been reported to decrease after the consumption of psyllium in most studies. Collectively, psyllium supplementation could be promoted to patients who present MS risk factors, such as hypercholesterolaemia, hypertriglyceridaemia and hyperglycaemia. It may also play a role in controlling body weight, body composition, appetite and hypertension, but further investigation is still required.

Effect of potassium supplementation on renal tubular function, ambulatory blood pressure and pulse wave velocity in healthy humans

BACKGROUND

Potassium is the main intracellular cation, which contributes to keeping the intracellular membrane potential slightly negative and elicits contraction of smooth, skeletal and cardiac muscle. A change in potassium intake modifies both cardiovascular and renal tubular function. The purpose of the trial was to investigate the effect of dietary potassium supplementation, 100 mmol daily in a randomized, placebo-controlled, crossover trial of healthy participants during two periods of 28 days duration. The participants (N = 21) received a diet that was standardized regarding energy requirement, and sodium and water intake.

METHODS

24-hour ambulatory blood pressure (ABP) and applanation tonometry were used to assess blood pressure, pulse wave velocity (PWV), augmentation index (AIx) and central blood pressure (CBP). Immunoassays were used for measurements of plasma concentrations of vasoactive hormones: renin (PRC), angiotensin II (Ang II), aldosterone (Aldo), atrial natriuretic peptide (ANP), vasopressin (AVP), pro-brain natriuretic peptide (pro-BNP),endothelin (Endo), urinary excretions of aquaporin 2 (AQP2), cyclic AMP (cAMP), and the β-fraction of the epithelial sodium channel (ENaC(ß)).

RESULTS

AQP2 excretion increased during potassium supplementation, and free water clearance fell. The changes in urinary potassium excretion and urinary AQP2 excretion were significantly and positively correlated. Aldo increased. GFR, u-ENaC- β, PRC, Ang II, ANP, BNP, Endo, blood pressure and AI were not significantly changed by potassium supplementation, whereas PWV increased slightly.

CONCLUSIONS

Potassium supplementation changed renal tubular function and increased water absorption in the distal part of the nephron. In spite of an increase in aldosterone in plasma, blood pressure remained unchanged after potassium supplementation.

The effects of 12-week psyllium fibre supplementation or healthy diet on blood pressure and arterial stiffness in overweight and obese individuals

Endothelial dysfunction and increased arterial stiffness occur early in the pathogenesis of the metabolic syndrome and they are both powerful independent predictors of cardiovascular risk. A high-fibre diet has been correlated with lower BMI and a lower incidence of hyperlipidaemia, CVD, hypertension and diabetes. The present randomised, parallel-design study compared the effects of fibre intake from a healthy diet v. fibre supplement diets on blood pressure (BP) and vascular function over 12 weeks. Overweight and obese adults were randomised to one of three groups: control (with placebo), fibre supplement (FIB) or healthy eating group with placebo (HLT). Systolic blood pressure (SBP) was lower in the FIB group compared with the control group at week 6, but not at week 12. However, SBP was lower in the HLT group compared with control group at week 12. At week 6, the FIB group presented lower diastolic blood pressure and augmentation index compared with the control group, but this result did not persist to the end of the study. The present study did not show any improvements in BP or vascular function in overweight and obese individuals with psyllium fibre supplementation over 12 weeks of intervention. However, a healthy diet provided the greatest improvements in BP in overweight and obese subjects. Further research with hypertensive individuals is necessary to elucidate whether increased fibre consumption in the form of psyllium supplementation may provide a safe and acceptable means to reduce BP, vascular function and the risk of developing CVD.

Acute effects of whey protein isolate on blood pressure, vascular function and inflammatory markers in overweight postmenopausal women

Previous evidence indicates that chronic consumption of dairy whey proteins has beneficial effects on CVD risk factors. The present study investigated the postprandial effects of whey protein isolate on blood pressure, vascular function and inflammatory markers in overweight and obese postmenopausal women. This was a randomised, three-way cross-over design study where twenty overweight and obese postmenopausal women consumed a breakfast meal in conjunction with one of three supplements: 45 g whey protein isolate, 45 g sodium caseinate or 45 g of a glucose control. Fasting and postprandial blood samples, blood pressure and pulse wave analysis readings were taken for up to 6 h. After consumption of the meal, both systolic and diastolic blood pressure, and augmentation index (AI) decreased initially for all interventions and gradually returned to baseline levels by 6 h. However, there were no significant differences in AI, systolic or diastolic blood pressure within or between the glucose control, casein or whey groups. There were also no significant group effects on plasma inflammatory markers (IL-6, TNF-α and C-reactive protein). The health effects previously seen with chronic whey protein ingestion were not seen in the acute 6 h postprandial period in relation to blood pressure, vascular function or inflammatory markers when compared with casein and a glucose control. This suggests that such effects are better observed from the long-term consumption of whey proteins.

The chronic effects of whey proteins on blood pressure, vascular function, and inflammatory markers in overweight individuals

Limited evidence suggests that dairy whey protein may be the major dairy component that is responsible for health benefits currently associated with increased dairy consumption. Whey proteins may reduce blood pressure and improve cardiovascular health. This study evaluated the effects of whey protein supplementation on blood pressure, vascular function and inflammatory markers compared to casein and glucose (control) supplementation in overweight/obese individuals. The subjects were randomized to either whey protein, casein or glucose supplementation for 12 weeks according to a parallel design. In all, 70 men and women with a mean (+/-s.e.m.) BMI (kg/m(2)) of 31.3 +/- 0.8 completed the study. Systolic blood pressure (SBP) decreased significantly at week 6 compared to baseline in the whey and casein groups, (P = 0.028 and P = 0.020, respectively) and at week 12 (P = 0.020, and P = 0.017, respectively). Diastolic blood pressure (DBP) decreased significantly compared to baseline in the whey and casein groups (P = 0.038 and P = 0.042, respectively) at week 12. DBP decreased significantly in the whey and casein groups (P = 0.025, P = 0.038, respectively) at week 12 compared to the control group. Augmentation index (AI) was significantly lower from baseline at 12 weeks (P = 0.021) in the whey group. AI decreased significantly in the whey group at 12 weeks compared to control (P = 0.006) and casein (P = 0.006). There were no significant changes in inflammatory markers within or between groups. This study demonstrated that supplementation with whey protein improves blood pressure and vascular function in overweight and obese individuals.

Determinants of a Blunted Carotid-to-Radial Pulse Wave Velocity Decline in Response to Hyperemia

Carotid—radial pulse wave velocity (PWV) decreases in normal healthy individuals following hyperemia provoked by release of arterial cuff occlusion. To determine the effects of specific cardiovascular (CV) risk factors on the hyperemic PWV response, we measured PWV before and after brachial artery (BA) occlusion in 218 participants (66% males, age 56 ± 19 years), with and without CV risk factors/disease. ΔPWV ranged from -46% to +35% and values were normally distributed. On univariate analyses, ΔPWV correlated with age, hypertension (Htn), hypercholesterolemia, diabetes mellitus (DM), coronary disease, congestive heart failure (CHF), smoking, and mean arterial pressure (MAP). On multivariate analysis, ΔPWV was independently related to Htn (B = 4.56, P = .03) and CHF (B = 7.34, P = .008) and trended toward a higher MAP (B = .113, P = .067), DM (B = 4.01, P = .11), and hypercholesterolemia (B = 3.36, P = .12). In conclusion, hyperemic changes in carotid—radial PWV values are independently related to Htn and CHF and possibly DM and hyperlipidemia.

Noninvasive measurement of central vascular pressures with arterial tonometry: clinical revival of the pulse pressure waveform?

The arterial pulse has historically been an essential source of information in the clinical assessment of health. With current sphygmomanometric and oscillometric devices, only the peak and trough of the peripheral arterial pulse waveform are clinically used. Several limitations exist with peripheral blood pressure. First, central aortic pressure is a better predictor of cardiovascular outcome than peripheral pressure. Second, peripherally obtained blood pressure does not accurately reflect central pressure because of pressure amplification. Lastly, antihypertensive medications have differing effects on central pressures despite similar reductions in brachial blood pressure. Applanation tonometry can overcome the limitations of peripheral pressure by determining the shape of the aortic waveform from the radial artery. Waveform analysis not only indicates central systolic and diastolic pressure but also determines the influence of pulse wave reflection on the central pressure waveform. It can serve as a useful adjunct to brachial blood pressure measurements in initiating and monitoring hypertensive treatment, in observing the hemodynamic effects of atherosclerotic risk factors, and in predicting cardiovascular outcomes and events. Radial artery applanation tonometry is a noninvasive, reproducible, and affordable technology that can be used in conjunction with peripherally obtained blood pressure to guide patient management. Keywords for the PubMed search were applanation tonometry, radial artery, central pressure, cardiovascular risk, blood pressure, and arterial pulse. Articles published from January 1, 1995, to July 1, 2009, were included in the review if they measured central pressure using radial artery applanation tonometry.

Disparities in vascular surgery: is it biology or environment?

Disparities in health care are well documented for several racial, ethnic, and gender groups. In peripheral arterial disease, differences in prevalence, treatment selection, treatment outcomes, and resulting quality of life have negative effects on some minority groups and women. It may be easy to document disparities, but it is harder to understand their underlying causes. Are there biologic differences between members of racial and ethnic groups that influence disease presentation and outcomes? Or is the socioeconomic environment that surrounds them the true driver of observed differences? This article reviews the evidence for racial and gender disparities in vascular surgery and presents some potential mechanisms that may explain the disparities.

Pulse wave velocity is more closely associated with cardiovascular risk than augmentation index in the relatively low-risk population

Pulse wave velocity (PWV) and augmentation index (AI) are both indirect indicators of arterial stiffness, which is an independent predictor of morbidity and mortality in cardiovascular diseases. The aim of this study was to assess the association between carotid AI (CAI), carotid-femoral PWV (CFPWV), and Framingham risk score (FRS), and to evaluate the factors determining CAI and CFPWV. Carotid AI and CFPWV were measured by applanation tonometry in 177 consecutive subjects without evidence of significant cardiovascular disease. Correlations between CAI and FRS and CFPWV and FRS were analyzed and major determinants of CAI and CFPWV were assessed. The mean age was 60.5 +/- 11.9 years and 112 (63%) of study patients were men. There was a significant association between CFPWV and FRS (r = 0.417, P < 0.001) and a weaker but also significant relation between CAI and FRS (r = 0.267, P < 0.001). CFPWV was significantly related to FRS in both men and women (P < 0.001 in both sexes), whereas the relation between CAI and FRS was significant only in women (P < 0.001). Our results suggest that CFPWV may be associated with CVD risk irrespective of sex, whereas CAI may be associated with CVD risk in women only.

Augmentation index, left ventricular contractility, and wave reflection

Augmentation index (AIx), a correlate of mortality, is thought to be influenced by left ventricular contractility and wave reflections. However, the relationship of AIx with left ventricular contractility changes has never been assessed, and the wave reflection theory has recently been questioned. This study sought to examine arterial waveform changes in response to reduced "wave reflection" and increased left ventricular contractility induced by dobutamine. Simultaneous radial tonometry (for AIx) and tissue Doppler echocardiography (for peak longitudinal systolic strain rate [SR] as an analogue of left ventricular contractility) were recorded at rest and peak dobutamine-induced stress in 50 patients (41 men; aged 62+/-10 years). From baseline to peak stress there was an increase in heart rate (70+/-11 to 127+/-17 bpm; P<0.001) and SR (-0.88+/-0.23 to -1.81+/-0.43 1/s; P<0.001), whereas AIx decreased (27+/-9% to -7+/-15%; P<0.001). There was also a greater increase in the systolic (compared with diastolic) pressure-time integral relative to cardiac cycle length (3.2+/-1.9 versus 1.8+/-1.1 mm Hg; P<0.001), indicating that wave reflection was not shifted into diastole as per the current belief. AIx was significantly associated with ejection duration (r=0.88), heart rate (r=-0.81), and SR (r=0.72; P<0.001 for all). However, when SR was heart rate corrected, there was no significant association with AIx (r=0.18; P=0.11). The strongest independent correlate of AIx was ejection duration, accounting for 78% variance (beta=0.88; model R2=0.77; P<0.001). Neither SR (beta=0.12; P=0.18) nor heart rate-corrected SR (beta=0.02; P=0.72) was associated with AIx. We conclude that AIx is determined by chronotropic rather than inotropic effects, as well as factors other than wave reflection.

Effect of Reactive Hyperemia on Carotid-Radial Pulse Wave Velocity in Hypertensive Participants and Direct Comparison With Flow-Mediated Dilation: A Pilot Study

This pilot study assessed the effects of hyperemia on carotid-radial pulse wave velocity (PWV) in 39 normotensive (NT) and 23 hypertensive (HT) participants using applanation tonometry. Pulse wave velocity was measured at 1- and at 2-minute intervals. Baseline PWV was similar between the groups (P = .59). At 1 minute, PWV decreased (8.5 ± 1.2 to 7.1 ± 1.4 m/s, P < .001) in NT but not in HT (P = .83). Hyperemic PWV (ΔPWV) response differed between the groups (-16% vs + 1.0%, P < .001). On multivariate analysis, HT, not age or blood pressure was independently related to ΔPWV (R2 = .43, P < .01). Among patients with cardiovascular risk factors/disease, ΔPWV was inversely related to flow-mediated dilation (FMD; R 2 = .43, P < .003). Conclusion: hyperemia decreases PWV1min in NT but not in HT. ΔPWV is inversely related to FMD. Blunted hyperemic PWV response may represent impaired vasodilatory reserve.

Location of arterial stiffening differs in those with impaired fasting glucose versus diabetes: implications for left ventricular hypertrophy from the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

To determine whether middle-aged and older individuals with impaired fasting glucose (IFG), but no clinical evidence of cardiovascular disease, exhibit abnormal changes in proximal thoracic aortic stiffness or left ventricular (LV) mass when compared with healthy counterparts.

RESEARCH DESIGN AND METHODS

From the Multi-Ethnic Study of Atherosclerosis, 2,240 subjects with normal fasting glucose (NFG), 845 with IFG, and 414 with diabetes, all aged 45 to 85 years and without preexisting coronary artery disease, underwent MRI determinations of total arterial and proximal thoracic aortic stiffness and LV mass. The presence or absence of other factors known to influence arterial stiffness was assessed.

RESULTS

After adjustment for clinical factors known to modify arterial stiffness, proximal thoracic aortic stiffness was not increased in those with IFG compared with those with NFG (1.90 +/- 0.05 versus 1.91 +/- 0.04 10(-3) mmHg(-1), respectively, P = 0.83). After accounting for clinical factors known to influence LV mass, LV mass was increased in those with diabetes relative to those with NFG (150.6 +/- 1.4 versus 145.8 +/- 0.81 g, P < 0.0009) but not in those with IFG in comparison with NFG (145.2 +/- 1.03 versus 145.8 +/- 0.81 g, P = 0.56).

CONCLUSIONS

Middle-aged and older individuals with the pre-diabetes state of IFG do not exhibit abnormal proximal thoracic distensibility or LV hypertrophy relative to individuals with NFG. For this reason, an opportunity may exist in those with IFG to prevent LV hypertrophy and abnormal aortic stiffness that is observed in middle-aged and older individuals with diabetes.

Characterization of arterial wave reflection in healthy bonnet macaques: feasibility of applanation tonometry

Nonhuman primates are commonly used in cardiovascular research. Increased arterial stiffness is a marker of subclinical atherosclerosis and higher CV risk. We determined the augmentation index (AI) using applanation tonometry in 61 healthy monkeys (59% female, age 1-25 years). Technically adequate studies were obtained in all subjects and required 1.5 +/- 1.3 minutes. The brachial artery provided the highest yield (95%). AI was correlated with heart rate (HR) (r = -0.65, P < .001), crown rump length (CRL) (r = 0.42, P = .001), and left ventricular (LV) mass determined using echocardiography (r = 0.52, P < .001). On multivariate analysis, HR (P < .001) and CRL (P = .005) were independent predictors of AI (R2 = 0.46, P < .001). Body Mass Index (BMI) and AI were independent predictors of higher LV mass on multivariate analysis (P < .001 and P = .03). In conclusion, applanation tonometry is feasible for determining AI. Reference values are provided for AI in bonnet macaques, in whom higher AI is related to HR and CRL, and in turn contributes to higher LV mass.